for using Wrath while HOTW is active ( U will need to manually activate HotW)
make an ability called Wrath - HOTW or whatever, using the ability editor.
Paste this into the large space on the right.
Code:
if UnitBuffID("player",108293)then
CastSpellByName(tostring(GetSpellInfo(5176)))
return true
end
Hit Save.
place it at the top of the rotation in the rotation editor.
you will need to manually shapeshift back into Bear form after the HotW buff expires. I can code it to do this automatically, but you will have issues if you need to Bress someone as it will consistently put u back into bear form.
I have tested the dmg differences between NV and Wrath though, and after you do , u may see that the overall dmg done is negligible (Wrath coming in about 800 dps higher). The healing NV provides to yourself and others during Gara'jal is much better utilized when you have Voodoo.
Before October 16th however, Wrath was kingpin, merely due to the fact HoTW provided 500% spell-power increase. it has since been nerfed to 320%.
- Anyway, there it is if you think its better 
Edit* After further testing on Elagon, HOTW is still better, but only if u reforge to haste, use haste trinkets (Trash drop and Shadopan trinkets are best)
Ended up with 160'ish k On Elagon doing this.